This invention relates to an apparatus for, and a method of, reconstructing and viewing a speckled holographic image, whereby the speckle of the holographic image is significantly reduced, without loss of resolution of the image.
Granular field noise, hereinafter referred to (as it is in the art) as "speckle", which masks the microstructure of recorded subjects, is inherent in holography. Continuing attempts have been made to reduce this effect, and many techniques have been tried. A diffuser in the scene beam of two-beam holography reduces the large diffraction noise to a fine-structured speckle. Phase plates, gratings, double holograms, and multi-color, multi-beam techniques have been tried with varying degrees of success.
Similarly, speckle reduction in reconstruction of the hologram has included: beam dithering or motion; extending the source area of the reconstructed beam; and, using a broad spectral line width light source. Speckle reduction by these, and other, techniques has been accompanied by a significant loss of resolution of the reconstructed holographic image.
I have invented an apparatus for, and a method of, reconstructing and viewing a speckled holograhic image, with the result that the speckle is significantly reduced without loss of resolution of the image. Thereby, I have advanced the state-of-the-art.